1. Field of the Invention
The present invention relates to a system and a method for spur cancellation.
2. Related Art
The operations of clocks, input devices, and output devices are among the most significant sources of spurs in a signal processing system, with the spurs occurring at the operating frequencies of these devices and at the harmonic frequencies of the operating frequencies. Prior techniques to address the problem of spurs include spur suppression and spur avoidance.
Spur suppression involves careful analysis of a circuit to determine an optimal arrangement of devices, traces, and ground attachments in the layout of the circuit to prevent spurs from developing. Unfortunately, if a situation arises that requires an alternative layout, another analysis of the circuit must be performed. Furthermore, an optimal arrangement of the layout does not prevent spurs from developing due to changes in temperature, voltage, or other parameters within the circuit.
Spur avoidance is accomplished by designing the circuit so that spurs occur at frequencies outside a desired band of frequencies. Unfortunately, while this technique works well for narrowband signal processing systems, it has limited applications in broadband signal processing systems.
What is needed is a technique for countering the effects of spurs in a broadband signal processing system. Preferably, such a technique would be flexible enough to accommodate both variations in the layout of the circuit and spurs that develop due to changes in temperature, voltage, or other parameters within the circuit.